The term CERN is also used to refer to the laboratory, which in 2013 had 2,513 staff members, and hosted some 12,313 fellows, associates, apprentices as well as visiting scientists and engineers[6] representing 608 universities and research facilities.[7]

CERN's main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research – as a result, numerous experiments have been constructed at CERN through international collaborations. The main site at Meyrin hosts a large computing facility, which is primarily used to store and analyse data from experiments, as well as simulateevents. Researchers need remote access to these facilities, so the lab has historically been a major wide area network hub. CERN is also the birthplace of the World Wide Web.

History

The 12 founding member states of CERN in 1954[1] (map borders from 1954-1990)

The convention establishing CERN was ratified on 29 September 1954 by 12 countries in Western Europe.[1] The acronym CERN originally represented the French words for Conseil Européen pour la Recherche Nucléaire (European Council for Nuclear Research), which was a provisional council for building the laboratory, established by 12 European governments in 1952. The acronym was retained for the new laboratory after the provisional council was dissolved, even though the name changed to the current Organisation Européenne pour la Recherche Nucléaire (European Organization for Nuclear Research) in 1954.[8] According to Lew Kowarski, a former director of CERN, when the name was changed, the acronym could have become the awkward OERN, and Heisenberg said that the acronym could "still be CERN even if the name is [not]".[citation needed]

The laboratory was originally devoted to the study of atomic nuclei, but was soon applied to higher-energy physics, concerned mainly with the study of interactions between subatomic particles. Therefore, the laboratory operated by CERN is commonly referred to as the European laboratory for particle physics (Laboratoire européen pour la physique des particules), which better describes the research being performed there.

Scientific achievements

Several important achievements in particle physics have been made through experiments at CERN. They include:

Based on the concept of hypertext, the project was intended to facilitate the sharing of information between researchers. The first website was activated in 1991. On 30 April 1993, CERN announced that the World Wide Web would be free to anyone. A copy[18] of the original first webpage, created by Berners-Lee, is still published on the World Wide Web Consortium's website as a historical document.

Prior to the Web's development, CERN had pioneered the introduction of Internet technology, beginning in the early 1980s. A short history of this period can be found at CERN.ch.[19]

Faster-than-light neutrino anomaly

On 22 September 2011, the OPERA Collaboration reported the detection of 17 GeV muon neutrinos, sent 730 kilometers (450 miles) from CERN near Geneva, Switzerland to the Gran Sasso National Laboratory in Italy, traveling apparently faster than light by a factor of 2.48×10−5 (approximately 1 in 40,000), a measurement with 6.0-sigma significance.[20] However, on 23 February, CERN stated in a press release that the results were flawed due to an incorrectly connected GPS-synchronization cable.[21] In March 2012, the ICARUS Collaboration reported that the measurement would be reproduced by both OPERA and ICARUS.[22] Further tests, after fixing the GPS connector, showed speed measurements consistent with the speed of light (or slightly below it) from four experiments at Gran Sasso, including OPERA.[21]

Particle accelerators

Current complex

CERN operates a network of six accelerators and a decelerator. Each machine in the chain increases the energy of particle beams before delivering them to experiments or to the next more powerful accelerator. Currently active machines are:

The On-Line Isotope Mass Separator (ISOLDE), which is used to study unstable nuclei. The radioactive ions are produced by the impact of protons at an energy of 1.0–1.4 GeV from the Proton Synchrotron Booster. It was first commissioned in 1967 and was rebuilt with major upgrades in 1974 and 1992.

The LHC tunnel is located 100 metres underground, in the region between the Geneva International Airport and the nearby Jura mountains. The majority of its length is on the French side of the border. It uses the 27 km circumference circular tunnel previously occupied by the Large Electron-Positron Collider (LEP), which was shut down in November 2000. CERN's existing PS/SPS accelerator complexes are used to pre-accelerate protons and lead ions which are then injected into the LHC.

Seven experiments (CMS, ATLAS, LHCb, MoEDAL,[24]TOTEM, LHC-forward and ALICE) are located along the collider; each of them studies particle collisions from a different aspect, and with different technologies. Construction for these experiments required an extraordinary engineering effort. For example, a special crane was rented from Belgium to lower pieces of the CMS detector into its underground cavern, since each piece weighed nearly 2,000 tons. The first of the approximately 5,000 magnets necessary for construction was lowered down a special shaft at 13:00 GMT on 7 March 2005.

The LHC has begun to generate vast quantities of data, which CERN streams to laboratories around the world for distributed processing (making use of a specialized grid infrastructure, the LHC Computing Grid). During April 2005, a trial successfully streamed 600 MB/s to seven different sites across the world.

The initial particle beams were injected into the LHC August 2008.[25] The first beam was circulated through the entire LHC on 10 September 2008,[26] but the system failed 10 days later because of a faulty magnet connection, and it was stopped for repairs on 19 September 2008.

The LHC resumed operation on 20 November 2009 by successfully circulating two beams, each with an energy of 3.5 teraelectronvolts (TeV). The challenge for the engineers was then to try to line up the two beams so that they smashed into each other. This is like "firing two needles across the Atlantic and getting them to hit each other" according to the LHC's main engineer Steve Myers, director for accelerators and technology at the Swiss laboratory.

On 30 March 2010, the LHC successfully collided two proton beams with 3.5 TeV of energy per proton, resulting in a 7 TeV collision energy. However, this was just the start of what was needed for the expected discovery of the Higgs boson. When the 7 TeV experimental period ended, the LHC revved to 8 TeV (4 TeV per proton) starting March 2012, and soon began particle collisions at that energy. In early 2013, the LHC was deactivated for a two-year maintenance period, to strengthen the electrical connections between magnets inside the accelerator and for other upgrades. In July 2012, CERN scientists announced the discovery of a new sub-atomic particle that was later confirmed to be the Higgs boson.[27] In March 2013, CERN announced that the measurements performed on the newly found particle allowed it to conclude that this is a Higgs boson.[28]

On 5 April 2015, after two years of maintenance and consolidation, the LHC restarted for a second run. Proton beams successfully circulated in the 27-kilometer ring in both directions. The first ramp to the record-breaking energy of 6.5 TeV was performed on 10 April 2015.[29][30] Operation continued in 2016, where the design collision rate could be exceeded for the first time.[31]

Possible future accelerators

CERN, in collaboration with groups worldwide, is investigating two main concepts for future accelerators: A linear electron-positron collider with a new acceleration concept to increase the energy (CLIC) and a larger version of the LHC, a project currently named Future Circular Collider.

Sites

Interior of office building 40 at the Meyrin site. Building 40 hosts many offices for scientists from the CMS and ATLAS collaborations.

The smaller accelerators are on the main Meyrin site (also known as the West Area), which was originally built in Switzerland alongside the French border, but has been extended to span the border since 1965. The French side is under Swiss jurisdiction and there is no obvious border within the site, apart from a line of marker stones. There are six entrances to the Meyrin site:[citation needed]

A, in Switzerland, for all CERN personnel at specific times.

B, in Switzerland, for all CERN personnel at all times. Often referred to as the main entrance.

C, in Switzerland, for all CERN personnel at specific times.

D, in Switzerland, for goods reception at specific times.

E, in France, for French-resident CERN personnel at specific times. Named "Porte Charles de Gaulle" in recognition of his role in the creation of CERN.[32]

Inter-site tunnel, in France, for equipment transfer to and from CERN sites in France by personnel with a specific permit. This is the only permitted route for such transfers. By the CERN treaty, no taxes are payable when such transfers are made. Controlled by customs personnel.[28][33]

The SPS and LEP/LHC tunnels are almost entirely outside the main site, and are mostly buried under French farmland and invisible from the surface. However, they have surface sites at various points around them, either as the location of buildings associated with experiments or other facilities needed to operate the colliders such as cryogenic plants and access shafts. The experiments are located at the same underground level as the tunnels at these sites.

Three of these experimental sites are in France, with ATLAS in Switzerland, although some of the ancillary cryogenic and access sites are in Switzerland. The largest of the experimental sites is the Prévessin site, also known as the North Area, which is the target station for non-collider experiments on the SPS accelerator. Other sites are the ones which were used for the UA1, UA2 and the LEP experiments (the latter which will be used for LHC experiments).

Outside of the LEP and LHC experiments, most are officially named and numbered after the site where they were located. For example, NA32 was an experiment looking at the production of so-called "charmed" particles and located at the Prévessin (North Area) site while WA22 used the Big European Bubble Chamber (BEBC) at the Meyrin (West Area) site to examine neutrino interactions. The UA1 and UA2 experiments were considered to be in the Underground Area, i.e. situated underground at sites on the SPS accelerator.

Participation and funding

Member states and budget

Since its foundation by 12 members in 1954, CERN regularly accepted new members. All new members have remained in the organization continuously since their accession, except Spain and Yugoslavia. Spain first joined CERN in 1961, withdrew in 1969, and rejoined in 1983. Yugoslavia was a founding member of CERN but quit in 1961. Of the 22 members, Israel joined CERN as a full member on 6 January 2014,[34] becoming the first (and currently only) non-European full member.[35]

Animated map showing changes in CERN membership from 1954 until 1999 (borders are as at dates of change)

Enlargement

Associate Members, Candidates:

Serbia became a candidate for accession to CERN on 19 December 2011, signed an association agreement on 10 January 2012[51][52] and became an associate member in the pre-stage to membership on 15 March 2012.[43]

Turkey signed an association agreement on 12 May 2014[53] and became an associate member on 6 May 2015.

Pakistan signed an association agreement on 19 December 2014[54] and became an associate member on 31 July 2015.[55][56]

Cyprus signed an association agreement on 5 October 2012 and became an associate Member in the pre-stage to membership on 1 April 2016.[44]

Ukraine signed an association agreement on 3 October 2013. The agreement was ratified on 5 October 2016.[47]

India signed an association agreement on 21 November 2016.[57] The agreement was ratified on 16 January 2017. [48]

Slovenia was approved for admission as an Associate Member state in the pre-stage to membership on 16 December 2016[49]

In popular culture

CERN's Large Hadron Collider is the subject of a (scientifically accurate) rap video starring Katherine McAlpine with some of the facility's staff.[66][67]

Particle Fever, a 2013 documentary, explores CERN throughout the inside and depicts the events surrounding the 2012 discovery of the Higgs Boson

CERN is depicted in an episode of South Park (Season 13, Episode 6) called "Pinewood Derby". Randy Marsh, the father of one of the main characters, breaks into the "Hadron Particle Super Collider in Switzerland" and steals a "superconducting bending magnet created for use in tests with particle acceleration" to use in his son Stan's Pinewood Derby racer. Randy breaks into CERN dressed in disguise as Princess Leia from the Star Wars saga. The break-in is captured on surveillance tape which is then broadcast on the news.[68]

In the popular children's series The 39 Clues, CERN is said to be an Ekaterina stronghold hiding the clue hydrogen.

In Robert J. Sawyer's science fiction novel Flashforward, at CERN, the Large Hadron Collider accelerator is performing a run to search for the Higgs boson when the entire human race sees themselves twenty-one years and six months in the future.

In season 3 episode 15 of the popular TV sitcom The Big Bang Theory titled "The Large Hadron Collision", Leonard and Raj travel to CERN to attend a conference and see the LHC.

The 2012 student film Decay, which centers on the idea of the Large Hadron Collider transforming people into zombies, was filmed on location in CERN's maintenance tunnels.[70]